Haha - you've got that right!
It can be darn tricky sometimes! Especially when you're dealing with a species that show little variation in terms of color/pattern between sexes.
The main cause of difficulty, IMO, is the fact that most of the traits that you go on when sexing these frogs don't become visible until sexual maturity, at which time such traits become quite obvious nearly simultaneously. It makes it kind of a guessing/waiting game, but it's all in good fun!